1. Field of the Invention
The present invention generally relates to a printing medium, and more particularly, to an inkjet photo-printing medium having a rapid ink absorption, a vivid color image, superb color fixation, a high water and light resistance, and glossiness.
2. Description of the Related Art
An inkjet printing apparatus forms an image on a printing medium by jetting fluid ink onto the printing medium through nozzles. The inkjet printing apparatus is very popular due to advantages that the inkjet printing apparatus makes little noise during a printing process and is easy to print a color image. The inkjet printing apparatus also has advantages in that the inkjet printing apparatus has a rapid output speed and is offered an economical price. The inkjet printing apparatus is thus widely applied to many printing devices like printers, facsimiles and plotters.
A general printing medium, which is effectively used in the inkjet printing apparatus having the above characteristics, is made by applying an ink receptive layer on a surface of a base layer like a sheet of paper made from an initial processing on pulp. The ink receptive layer has a characteristic that enables it not only to absorb liquid ink sufficiently but also to clarify a picture image. The ink receptive layer is disposed on the base layer as an applicator is applied to the surface of the base layer. The applicator is made as a pigment, such as silica, and is distributed within a binder resin like a polyvinyl alcohol.
Various printing media are used in the inkjet printing apparatus, including a regular paper, a special-purpose coated paper, a special-purpose film, and a photo printing medium. A inkjet photo printing medium is made by coating a substance, which has superior ink absorption and fixation and a high liquid and light resistance, onto the base layer of the printing medium like one-sided or double-sided art paper, cast coated paper, and photographic paper. The printing medium is used in printing digital photos or images through a thermal type, piezo type or phase change-type inkjet printing apparatus. The printing medium is also used in other applications like outdoor decorations, designs or advertisement.
Here are a few examples of such an inkjet-printing medium. U.S. Pat. No. 5,866,268, entitled Liquid sorptive coating for ink jet recording media to ARKWRIGHT INC., and the Japanese Patent publication No. 55-144172, entitled Ink jet recording method to FUJI PHOTO FILM CO., LTD., disclose a recording medium using a hydrophilic binder like copolymer of cellulose derivative and polyvinyl alcohol. The disclosed recording medium, however, has a shortcoming of a weak liquid resistance that causes a printed image often to gravitate and be blurred especially when the recording medium is put under water within ten (10) minutes after the printing. Japanese Patent Publication No. 59-198186 entitled Recording material to Canon KK discloses the use of the recording medium using organic acid salt of polyethyleneimine to improve the water resistance. There are, however, problems of deteriorating heat and light resistance and subsequent yellowing of the recording medium by an ultraviolet (UV) light.
Japanese Patent publication No. 60-232990 entitled Inkjet recording medium to MITSUBISHI SEISHI and Japanese Patent Publication No. 6-199035 entitled Material on which recording is made to ASAHI GLASS CO., LTD., also disclose the recording medium using both an alumina hydrate and a water soluble binder, which has a superb water resistance and a glossiness but with a shortcoming of deteriorating ink absorption.